Electrical devices are dependent on electrical energy. Electrical energy is often made available via a distribution network. Overvoltage can occur due to faulty circuits, network failures, lightning strikes, or other phenomena.
Such overvoltage poses a hazard for connected electrical equipment (and for the distribution network as well). It can result in a malfunction or to damage ranging all the way to total destruction.
For this reason, many electrical devices (and/or their distribution network) are equipped with overvoltage protection, whether to protect investments or to comply with normative requirements.
This overvoltage protection is fault-prone, however, whether due to excessive power to be discharged or frequent response as a result of excess voltage. Such faults can lead to the destruction of the overvoltage protection element, to pronounced thermal heating, or even to fires and the development of smoke gas, which are potentially hazardous for equipment and people in the environment.
If a fault occurs, then the corresponding overvoltage protection element is either disconnected by means of suitable devices, thereby interrupting the power supply, or short-circuited in order to trigger the disconnection of an upstream in-line fuse.
One example of an isolating arrester is the thermal fuse known from DE 90 102 46 U1, for example, which is associated with a component in order to enable shutdown upon heating.
Due to the limited thermal coupling possibilities, this arrangement is not suitable for very rapid temperature increases.
Other devices for disconnection or short-circuiting are described in the applicant's patent DE 42 41 311 as well as in DE 699 04 274 T2 and in U.S. Pat. No. 6,430,019.
The solutions described in the above documents are based on the principle that the component to be monitored is connected in a thermosensitive manner via a contact element, generally a solder connection. The contact element mounted so as to be prestressed, or a force of a second prestressed element, such as a spring, acts on the contact element. If the spring force exceeds the cohesion of the thermosensitive contact point, e.g., soldering point, the contact opens and the monitored component is switched off.
However, the previous arrangements are extremely space-consuming and expensive to manufacture.
It would therefore be desirable for solutions to be provided that can be used in small installations and/or can be manufactured cost-effectively.
In addition, it would be desirable for a device to be provided that can also be used for a multitude of components to be monitored and/or can be manufactured cost-effectively.